PAS positive glycoproteins appear to accumulate in type II alveolar cells or in alveolar spaces in many lung diseases. An unusual glycopeptide with asparagine-linked carbohydrate has been found in alveolar proteinosis. The objectives of our study are to compare the products of this pathway with the known structures of glycopeptides found in the disease state and to determine what variations (such as the nature of the lipid carrier, oligosaccharide components, and effect of inhibitors and drugs) might be unique to lung tissue. At this point we have isolated a glycopeptide which is labeled with 14C mannose via the lipid-linked pathway of oligosaccharide synthesis in lung homogenates. This glycopeptide has a molecular weight of 40,000-50,000 daltons and is rich in serine, glycine, glutamine and asparagine. Other work includes the demonstration that retinol may modulate oligosaccharide synthesis in lung parenchyma and may also serve as a lipid carrier of individual carbohydrates. Research goals for the coming year include repeating many of the above studies in type II cell preparations and lung fibroblast cultures. The purpose of these studies is to determine whether these cells synthesize the glycoprotein described above. If enough glycoprotein can be isolated, further studies including limited enzymatic digestion of the oligosaccharide will be carried out to determine the sialic acid, furose and galactose content of the oligosaccharide. Further studies to determine the monosaccharide components of the newly synthesized oligosaccharide will also be carried out if enough oligosaccharide can be produced. We wish to have this information to compare the oligosaccharide with oligosaccharides found in alveolar proteinosis.